Term 4 NotesForces and Motion & Engineering

MotionMotion: is the change of position or

location over a certain length of time.Basically motion is the movement of

an object.Motion is the result of an applied

force.In Physics motion is usually measured

in terms of velocity and speed.

For an object to move there must be a force that is applied to it.

No object can move on it’s own.An object that is not moving is said

to be at rest.

Types of MotionThere are three types of motion.1)Translational Motion This is the when an object moves in a

straight line. Ex: Car, bike2) Rotational Motion This is when an object moves in a

circle. Ex: Merry-go-round, wheel3) Spiral Motion This is when an object moves in spiral.

Ex: Cork screw, screw

All the dots in the animation are showing translational motion

All dots are moving in a straight line. But are travelling in different directions.

The wheels are showing rotational motion.

Wheels are moving in a circle.

The blade is moving in a spiral motion

The blade is moving in a circle and straight at the same time this produces a spiral.

ForceIn Physics a force is any action that

allows an object to move.Ex: pushing a shopping cart A force can also change the speed or

direction (trajectory) of an object that is already in motion.

Ex: curling, pool, bocceFinally a force can deform (change

the shape) of an object.Ex: stretching an elastic, leggings

Types of forceThere are five types of force1) Tension This force will stretch an object Ex: bow and arrow, elastic

2) CompressionThis force will compress (squeeze) an

object.Ex: squeezing a sponge, crushing a

can

3) Torsion This force will twist an objectEx: opening a jar, twisting your

ankle.

4) FlexionThis is the force that will bend an

object.Ex: your spine, pole vault

5) ShearingThis is the force that will tear an

object.Ex: tearing a piece of paper,

earthquake

Effects of a ForceAs mentioned above an object needs

a force to move.No object will move on its own.Therefore, the effects of a force is

motion.Even the human body is a complex

system of forces.In one movement the human body

can experience all five forces.

Mechanisms that transmit Motion

Motion can be transmitted to other components in a system.

A mechanism that transmits motion is will transfer motion of the same type to another component in a system.

In many systems oil and water are used as these mechanisms.

Ex: Hydraulics and hydro dams

Other components can be used to transfer motion.

Components like; gears, pulleys, belts, and chains all work together to transfer motion.

Describe how motion is transmitted in a bicycle

1. Force applied by the rider’s legs. Which causes the pedals to move (translational motion)

2. The arms of the pedals move in a circle (rotational motion)

3. The chain move backwards (translational motion) towards the back gears.

4. The back gear rotates which is attached to the rear wheel.

5. This allows the bicycle to move forward

Simple MachinesA simple machine is a mechanical

device that will change the direction of a force.

A simple machine uses one type of force to move an object.

There are 6 classical simple machines; lever, pulley, wheel & axle, inclined plane, wedge, screw

Provide one example of how each would be used

1. Lever: Hammer, letter opener, car jack

2. Pulley: clothes line, elevator3. Wheel & Axle: Car, bike4. Wedge: Axe, chisel5. Inclined plane: ramp, see-saw6. Screw: screw, cork screw

Mechanisms that bring about a change in Motion

Any object that is in motion can have its speed and direction changed.

This change would occur if another force is applied to this object.

An object being squeezed then stretched. Ex: dough

Ex: A ball bouncing off a wall Ex: Car crash.

DrawingsDrawings, images, and pictures are

used in our everyday lives.Drawings can be used to represent

an event, action, person, or a law.In many circumstances a drawing or

picture can be clearer than a verbal or written explanation.

Some images have become so recognizable that no words are needed at all.

Identify these images

Types of DrawingsDrawings are most often used in

construction.Drawings serve to illustrate how

various parts will connect with one another.

Furthermore, drawings will show dimension.

Finally a drawing can depict how to put an object in motion.

Drawings can also serve as instructions in the making of a technical object.

There are three types of drawings one can use.

1) SketchA sketch is a freehand drawing that

depicts a design of an object.It will show the shape and some

dimensions of an object.It will also help in the creation of

other drawings

2) Design PlanA simplified drawing showing the

function and operating principles of an object.

This type of drawing does not include any measurements or list of materials.

3) Technical DrawingIs a simplified drawing showing the

materials and steps to get the object to its final functioning form.

It may also be necessary to include several angles (front, top, side views)

This type of drawing also includes how different pieces will be connected.

There are 12 basic lines that one can use in a technical drawing

Manufacturing Process SheetA manufacturing process sheet is a

document similar to a set of instructions.

This document includes every step required to manufacture a technical object.

It provides the order in which steps need to be carried out.

It also gives the time allotted for each step

Materials, Raw Materials, and EquipmentThe manufacturing of technical

objects requires a diverse set of materials.

Material: any substance used to make things.

Materials are classified by the origin of their raw materials.

Materials include things like: wood, glue, staples, paper, metals, etc.

Raw materials: a natural material that has not been transformed into materials that can be used.

Raw materials are unprocessed.There are three major categories of

raw materials.1. Wood substances: hard and soft

wood2. Minerals: Iron, copper, steel, etc.3. Crude oil: plastic, polymer, nylon,

etc.

Equipment: are the tools, instruments, and machines that create technical objects.

Equipment could be as simple as a pencil, scissors, toothpick, etc.

Equipment are technical objects themselves.

Every piece of equipment is made up of materials and followed a process in its manufacturing.

SpecificationsSpecifications is a document that provides a detailed description of needs and demands.

A technical object will have a specific function, therefore it needs to be built in a certain way.

For example, a bridge must be able to withstand strong winds, precipitation, and natural hazards.

Lab ExamReview

Mass and VolumeTo measure the volume of a liquid

simply read the measurement off of a graduated cylinder.

NOTE: be sure to read the bottom of the meniscus.

Volume is the amount of space taken up by an object

Volume of a cube:V= s x s x s

(All sides of a Cube are equal)

S

S

S

Volume of a rectangular prism:

V= l x w x h

w

h

l

To measure the volume of an irregular shaped object, ex: rock, use the water displacement method.

Water displacement method:1. Fill a graduated cylinder with a

known quantity of liquid.2. Place the object in the cylinder 3. Follow this formula

V= Vf (water with object) – Vi (just water)

Mass is very easy to calculate.Simply place the object on a scale or

balance.Use of the triple beam balance will

be explained in the lab.

Example Problems1. Volume of a cube with a side of

5.7 cm.2. Volume of a rectangular prism

with a length of 10cm, width of 6.3cm, and height of 2cm

3. Volume of a rock that raised the water in a graduated cylinder(GC) 10ml from the original 25ml.

DensityMass and volume are not considered

characteristic properties.This is due to the fact that many

objects could have the same mass and volume.

In these cases one would have to calculate the density of the objects.

Density: measures the amount of matter (particles or stuff) in a substance.

To calculate the density of an object one must know the mass and the volume.

Density is calculated using the following formula:

D = m/v

The formula reads density is equal to mass divided by volume.

The units for density are g/ml

Example problems

1. Density of an object with a mass of 8.9g and a volume of 3.3ml.

2. Density of a substance with a mass of 130g and a volume of 40ml.

3. Density of a cube with a mass of 25g and a side of 1.3cm.

4. Density of a bracelet with a mass of 8g and raised the water in a GC 3ml from 10ml.

Acidity and Alkalinity

pH is the measure of how acidic or how basic (alkalinity) a solution is.

pH scale measures solutions (liquids)The pH scale has a range of 0-14.If a solution falls into the 0-7 range it

is an acid, 7-14 it is a base (alkaline).0 = battery acid, 14 = drain cleanerIf a solution is 7 it is neutral ex: pure

water.

Using a microscope: Page 311 in your textbooks